Gecode 4.4.0

This release fixes some bugs and improves some search-related aspects.

Note that you will have to change all scripts that inherit from the pre-defined script classes (Script, IntMinimizeScript, IntMaximizeScript, FloatMinimizeScript, FloatMaximizeScript). The change is easy: in your constructor you have to add a call to the constructor of the pre-defined script class with the command line options as argument. Just check any of the Gecode example for how it is done.